Crusher jaw construction



United States Patent 3,241,777 CRUSHER JAW CONSTRUCTION Robert S. Kuntz, Nashwauk, Minn., assignor to The Hanna Mining Company, Cleveland, Ohio, at corporation of Delaware Filed Apr. 8, 1965, Ser. No. 446,549 9 Claims. (Cl. 24ll3tl0) This application is a continuation-in-part of my earlier application Serial No. 262,115, filed March 1, 1963, now abandoned, and entitled Crusher Jaw Construction, and similarly relates to improved jaw constructions for use with jaw-type crushers.

In known jaw crushers of the overhead eccentric type, with which the improved crusher jaws of the present invention are especially adapted for use, excessive wear of the jaws, attended by frequent and costly replacement thereof, has been a constant problem. By the very nature of the mounting and action of the movable jaw, uneven wear thereof results, with the area of greatest wear being found to occur in the lower portion of the jaw adjacent the discharge opening. The underlying reason for the repeated occurrence of this problem of uneven wear is that present crusher jaws are normally designed to desirably meet requirements of both adequate surface hardness to resist the abrasive action encountered during crushing and resistance to the impact and compression forces which accompany the crushing operation, with corrugated crushing plates being exemplary of present constructions. To date, the difiiculty of casting crusher jaw faces which have these desired properties has resulted in an undesirably short useful jaw life, consequently resulting in frequent and costly replacement or repair.

With the above in mind, it is a primary object of the present invention to provide a crusher jaw having a hard, abrasion-resistant crushing surface and a body construction particularly adapted to resist the impact and compression forces encountered during operation. A more specific object is to provide a novel crusher jaw construction wherein the crushing elements forming the crushing surface'can be metallurgically controlled separately from the jaw body upon which they are mounted, whereby the crushing elements can be designed for maximum wear and abrasion resistance and the jaw body can be separately designed for maximum impact and compression resistance.

Another object of the present invention is to provide such a crushing surface wherein the resistance to wear and abrasion can be selectively varied over the surface thereof to compensate for variation in the subjection thereof to such wear and abrasion.

Yet another object of the invention is to increase crushing efficiency by providing a multiple point crushing surface.

Still another object of the invention is to substantially reduce crushing surface replacement costs by providing a crushing surface comprising a plurality of hardened steel ball members independently mounted in the jaw body for individual replacement, with the ball members comprising a relatively small percentage by weight of the entire jaw construction including the jaw body. In accordance with one form of the invention, the individual balls are fastened in operative position to provide simple and quick removal and installation, and in further forms of the invention the balls are mounted relatively more permanently in the jaw body but yet are readily removable therefrom in accordance with the invention teachings.

A further object of the invention is to provide in certain forms thereof a ball mounting arrangement designed effectively to decrease the forces transmitted during the crushing operation from the crushing balls to the jaw body.

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A still further object of the invention is to provide in certain forms thereof a ball mounting arrangement which minimizes the machining required of the jaw body.

Another object of the present invention is to provide a jaw construction which can be reversed from top to bottom while maintaining the same crushing pattern.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In the annexed drawings:

FIG. 1 is a schematic elevational view showing one form of crusher jaws in accordance with the present invention mounted in a typical overhead eccentric type of jaw crusher;

FIG. 2 is a fragmentary plan view of the stationary crush-er jaw body of the FIG. 1 form;

FIG. 3 is a sectional view through the jaw body taken on lines 33 of FIG. 2;

FIG. 4 is an enlarged, partially sectioned, view of the FIG. 1 form of the invention, showing the manner in which the balls utilized for crushing are removably mounted in the jaw body;

FIG. 5 is an enlarged, fragmentary, sectional view showing a modified form of mounting the balls on the jaw body;

FIG. 6 is an enlarged, fragmentary, sectional view of another form of mounting the balls on the jaw body, and

FIG. 7 is an enlarged, fragmentary, sectional view of a still further form of mounting the balls on the jaw body.

Referring now to the drawings, wherein like parts are indicated by like reference characters, and initially to the FIGS. 1-4 form of the invention, FIG. 1 illustrates schematically a typical overhead eccentric type crusher, generally indicated at 10, with which the crusher jaw construction of the present invention is adapted for use. The structural details of the crusher as a combination or machine have not been illustrated and form no part of the present invention, such structure being shOWn only to the extent necessary for a complete understanding of the present improvements. In this regard, although the crusher jaw construction of the invention has been shown associated with a crusher of the overhead eccentric type, it will become apparent that the principles embodied in the present invention afford a far broader use of the novel jaw construction and the invention is accordingly not intended to be limited to the illustrated environment.

The crusher 10 includes a frame 12 on which an eccentric shaft 14 is journaled, such shaft being driven by conventional means (not shown). The frame 12 has rigidly secured thereto a stationary jaw base 16 and an oppositely disposed base member 18 to which the bottom of a pitman or movable jaw 20 is operatively connected for movement relative thereto. The lower end of the pitman 20 is spaced from the frame member 18 by means of a toggle plate 22, one end of which is received in a toggle seat 24 on the pitman 20 and the other end of which is seated in a vertically adjustable wedge member 26 positioned on the frame member 18. The toggle plate is held in the illustrated position in the usual manner by means of a tension rod and spring (not shown) which permit movement of the toggle plate 22 during movement of the pitman 2t responsive to rotation of the eccentric shaft 14. The pitman 20 has mounted by any suitable means on the inner face thereof a movable jaw construction generally indicated at 27 comprising a crusher jaw body 28 on which are mounted crushing elements to be hereinafter described in detail, such elements forming a crushing surface cooperable with a similar crushing surface provided on the jaw body 30 of a stationary jaw generally indicated at 31. The stationary jaw 31 is mounted in any suitable, wellknown manner on the stationary base 16. Mounted on the frame 12 at both ends of the fixed and movable jaws are suitable liner members (not shown) which define with the fixed and movable jaws 27 and 31, respectively, a material inlet opening 32 and a discharge opening 34.

In a manner well-known to those familiar with jaw crushers of the illustrated type, the material to be crushed is fed to the crusher through the material inlet 32. Rotation of the eccentric shaft 14 effects movement of the pitman 20 and the material is crushed between the crushing surfaces of movable jaw 27 and the fixed jaw 31 as it progresses downwardly between the same. Due to the eccentric shaft 14, the movement of the pitman 20 at the upper end thereof adjacent the eccentric shaft is generally circular, this movement gradually changing to an ovate motion and then to an essentially linear motion in the area thereof inwardly of the mounting of the toggle plate 22. This generally ovate and essentially linear movement of the intermediate and lower portions, respectively, effects downward crowding of the material in such areas. In opposition to this crowding action during part of each stroke, the remaining part of each stroke tends to lift the material against the stationary jaw 31. Since this lifting action becomes more pronounced as the movement of the movable jaw 27 approaches linearity, the abrasion of the faces of the jaws 27 and 31 is likewise more pronounced at the lower ends thereof adjacent the discharge opening. The result of this uneven abrasion in crushing jaw plates of known construction is that the lower portions thereof wear away at a more rapid rate than the upper portions, thereby leading to premature and costly replacement of the entire jaw face. This cost factor of replacement has been alleviated somewhat by the provision of reversible jaw plates which can be reversed from top to bottom. However, even with this reversibility feature, the jaw plates must necessarily simultaneously provide the required resistance to impact and compression forces encountered during the crushing operation, and the presence of this latter characteristic in the normally alloyed casting has been at the sacrifice of abrasion resistance in the crushing surface.

The present invention seeks to overcome the noted disadvantages of present crusher jaws by providing a construction wherein each crusher jaw, both movable and stationary, comprises a body portion specifically designed to absorb the relatively high impact and compression forces encountered during crushing, and a plurality of hardened steel balls which are mounted in the jaw body to provide the crushing surface. In accordance with the several forms of the present invention, the hardened steel balls are mounted in the jaw body in various manners for selected, independent removal and installation, thus enabling the crushing surface to be metallurgically controlled to an extent not before possible.

Referring further to the crusher jaw construction illustrated in FIGS. l-4 of the invention, the stationary crusher jaw body 30 is shown in FIGS. 2 and 3 without the hardened steel bodies mounted therein. Inasmuch as the construction of the movable jaw body is essentially identical, a separate description thereof is not believed necessary. The jaw body 30 is provided with a plurality of parallel rows of spaced openings which are generally indicated at 36, with the openings of each row being offset or staggered with respect to those of the adjacent rows. Each opening 36 is adapted to receive a hardened steel ball which will be hereinafter described when particular reference is made to FIG. 4. Each of the openings 36 extends transversely through the jaw body and comprises, referring to FIG. 3, a semi-spherical upper portion 38, an intermediate cylindrical portion 40 provided with a countersunk portion 42 at the upper end thereof, and a bottom portion 44 communicating with the underside of the jaw body. As can be seen in FIG. 2, the portions 44 together form a longitudinally extending bottom or outer channel 45 which extends beneath the entire row to facilitate replacement of the balls. The jaw body 30 is further provided with downwardly depending flanges 46 at opposite ends thereof for mounting the body on the stationary jaw base 16. A plurality of openings 48 are provided at opposite side edges thereof for receiving mounting bolts (not shown) which extend therethrough into the base 16 for rigidly securing the jaw body thereto.

Referring to FIG. 4, the upper portion 38 of each opening 36 is adapted to receive a hardened steel ball generally indicated at 50. Each steel ball 50 seats in the semispherical upper portion 38 of the opening 36 and is provided with a flattened bottom surface 52 against which a threaded shank 54 is rigidly secured, for example by welding, as shown. The threaded shank 54 extends freely through the intermediate portion 40 into the bottom portion 44 of the opening 36, and a nut 56 and washer 58 are provided for removably securing the ball in place. It will accordingly be seen that each of the steel balls 50 can be simply and quickly mounted or removed from the jaw body, either independently or as a group.

The openings 36 in the jaw bodies 28 and 30 are arranged so that the jaw bodies can be reversed from top to bottom without altering the crushing pattern, such pattern also being a distinctive feature of the present invention. By providing a plurality of steel balls which extend from each of the jaw bodies into the crushing zone, multiple point loading or crushing is provided, as contrasted to presently existing flat or corrugated crushing surfaces. The multiple point loading provides a bridging action between opposed balls thereby providing increased crushing etficiency.

There are shown in FIGS. 5-7 alternative forms of mounting the steel balls in the openings in the jaw body. In all of these further forms the ball is mounted in or on a zinc or like casting in such a manner as to reduce the machining required on the jaw body casting.

Referring initially to the modification of FIG. 5, which comprises a fragmentary sectional view taken through one portion of the jaw body casting 60, the body is formed with a plurality of openings, exemplified by opening 62, which are preferably formed in a pattern generally similar to that previously described with regard to the FIGS. 1-4 form of the invention. Each opening 62 is cast countersunk adjacent the lower end thereof to provide annular shoulders 64 and 66. In this form the steel ball 68 is precast in a zinc or like relatively soft metal base 70 having a cylindrical exterior to adapt the same for disposition in the circular opening 62. The ball has secured thereto, for example by welding, a stud 72 having a flange 74, the stud serving to anchor the ball in the zinc base.

The zinc base 70 is formed with a radially enlarged flange 76 which is adapted to engage shoulder 64 for properly axially positioning the ball within the jaw body. The ball 68 and zinc base 70 thus comprise a ball unit or assembly which can be easily positioned in the jaw body. The ball assembly is held in the opening 62 by means of a preferably steel disc 78 the radial edges of which engage the shoulder 66 formed in the jaw body. The disc or washer 78 can be tack welded as indicated at 80 to the aw body thereby to secure the ball unit in place until the jaw body is placed in the crusher frame.

It will be noted that a thin annular layer 82 of zinc separates or spaces the ball 68 from the wall of the opening 62 formed in the jaw body whereby the forces encountered by the ball 68 during the crushing operation are transmitted through the zinc to the body rather than from the ball directly to the jaw body. The zinc being relatively soft thus provides a cushioning effect and thus reduces the loading of the ball against the casting. Further, the employment of the unitary ball and zinc base eliminates the need for machining the jaw body casting to receive the spherical crushing ball.

Although the ball assembly can be removed from its mounted position by manually fracturing or otherwise destroying the tack weld 80 thereby permitting downward withdrawal of the disc or washer 78 and the ball assembly, the ball units are preferably punched out by means of a press or the like, with the press head engaging the exposed end of the ball and forcing the unit or cartridge downwardly thereby fracturing the localized tack weld 80 and forcibly moving the ball unit from its mounted position in the jaw body. It will be apparent that, dependent upon the available equipment and other considerations, the ball units may be removed individually or in selected groups or as an entire group. Following punch-out of the ball uni-ts, the walls of the exposed openings 62 are cleaned for the reception of replacement ball units.

In a further modified form of the invention illustrated in FIG. 6, which similarly comprises a fragmentary crosssectional view through the jaw body casting, the jaw body 83 is formed with a plurality of downwardly and inwardly tapered openings 84 which are preferably formed in the jaw body in a pattern generally similar to that above described. The upper region of each of tapered openings 84 receives and supports a crushing ball 86, with the diameter and taper of such opening being selected to properly support the ball for the desired penetration of the exposed end thereof into the crushing area. In this form of the invention the zinc base 88 is cast in situ following placement of the ball in the opening, with the zinc in the form shown filling up slightly more than half of the opening 84 below the ball 86. The latter has connected thereto at the lower end thereof a stud 90 having a flange 92 which serves to anchor the ball in the cast zinc base. An undercut 94 is preferably formed in the jaw body casting to lock the casting to the jaw body.

The FIG. 6 form similarly minimizes the machining required of the jaw body; and during the crusher operation, the relatively great forces acting on the respective balls 86 tend to expand the Zinc into the interface between the ball and the jaw body. The penetration of the zinc into the interface serves to decrease the direct loading of the ball against the jaw body.

To remove a single, several or the entire group of balls 86 from the jaw body for replacement or the like, the jaw body is removed from the base member and a punch press is employed to punch out the respective zinc castings and balls cast thereto. The punch-out is effected by disposing the jaw body so that the bottom of the same is exposed to the punch member or members of the press. The punch member consequently contacts the bottom of the zinc casting 88, and under relatively large press forces the zinc base and ball attached thereto are forced outwardly of the opening 84. Subsequent to the complete removal of the ball unit, the opening 84 and undercut 94 are cleaned to prepare the same for replacement ball units.

The FIG. 7 form of the invention is similar to that illustrated in FIG. 6, with the jaw body 95 being formed with a group of openings each of which comprises a tapered top portion 96 and a cylindrical bottom portion 98. The ball 100 is similarly positioned in engagement with the wall of the tapered opening 96, and the zinc base 102 poured and cast in situ. A flanged stud 104 is similarly provided for anchoring purposes. The ball and zinc base can be removed by a punch press in the same manner as described above in reference to the FIG. 6 form.

It will now be apparent that the present invention provides distinct advantages over present crusher jaw constructions. By providing a plurality of independent, separately mounted and removable steel balls or ball units, the resistance to abrasion of the crushing surface can be varied as desired to provide an optimum crushing surface for a particular material or operation. A crushing surface can be provided giving relatively uniform wear throughout, thereby not only increasing crushing efficiency but greatly reducing replacement costs. Further, the balls can be metallurgically controlled separately from the jaw body casting itself thereby providing the desired characteristics in each. The jaw body can be metallurgically designed for maximum shock and impact resistance without unnecessary regard for resistance to abrasion. Similarly, the hardened steel balls can be designed having primarily in mind a relatively high resistance to abrasive wear. The jaw body is thus relatively permanent with only the balls, which approximate 25 percent of the weight of the entire jow construction, being replaced when necessary, thereby further reducing replacement costs.

In the FIGS. 5-7 form of the invention, the machining required of the jaw body has been reduced to a minimum and, although the ball unit constructions of these forms are somewhat more rigidly secured, the units can nevertheless be quickly removed by means of a conventional punch press machine in the manner described.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. Jaw construction for use in crushers and the like comprising a jaw body having a plurality of openings formed therein, said openings being formed in a series of parallel spaced rows, with the openings in any one row being staggered relative to the openings in the adjacent rows on either side thereof, each of said openings receiving a hardened steel ball which projects from the jaw body to provide a working surface to material in all directions of movement of such material over said jaw body and means for removably securing said ball to said body.

2. The jaw construction of claim 1 wherein said body is formed with a series of channels beneath each of said parallel rows, each of said balls is provided with a threaded extension which extends into a respective channel, and wherein said locking means comprises fastener means each of which is disposed in a respective channel and threadedly engages a respective extension for removably securing said ball in said opening.

3. The combination of claim 1 wherein the surf-ace of said jaw body adjacent said balls is curved.

4. Jaw construction for use in crushers and the like com-prising a jaw body having a plurality of openings formed therein, said openings being formed in a series of parallel, spaced rows, with the openings in any one row being staggered relative to the openings in the adjacent rows on either side thereof, each of said openings receiving a hardened steel ball which projects from the jaw body to provide a working surface to material in all directions of movement of such material over said jaw body, with the hardness of said balls being selectively and individually variable to adapt the jaw construction for crushing of particular and variable materials, and means for mounting said balls on sid body.

5. Jaw construction for use in crushers and the like comprising a jaw body having a plurality of spaced openings formed therein, a plurality of separately formed ball units mounted in and partially projecting from said openings, the surface hardness of the projecting portion of each of said ball units being selectively and individually variable independently of the surface hardness of said jaw body thereby to provide a crushing surface having a particular hardness pattern, and means for mounting said ball units on said jaw body.

6. The combination of claim 5 wherein each of said ball units comprises a hardened steel ball secured to a cast metal base, with approximately one-half of said ball projecting from the surface of said jaw body into the crushing region.

7. The combination of claim 6 wherein said ball and said metal base are of unitary construction when placed in said opening.

8. The combination of claim 6 wherein each of said openings in said jaw body is at least partially outwardly tapered, said ball being received on and supported by said tapered portion, a metal base conforming to and supporting the lower portion of said ball in said opening, and means for anchoring said ball in said base.

UNITED STATES PATENTS 273,477 3/1883 Dodge 241300 2,252,351 8/1941 Paulus 29149.5 2,851,225 9/1958 McMah'an 24130O 2,932,081 4/1960 Witte 29-149.5

ROBERT C. RIORDON, Primary Examiner. 

1. JAW CONSTRUCTION FOR USE IN CRUSHER AND THE LIKE COMPRISING A JAW BODY HAVING A PLURALITY OF OPENINGS FORMED THEREIN, SAID OPENING BEING FORMED IN A SERIES OF PARALLEL SPACED ROWS, WITH THE OPENINGS IN ANY ONE ROW BEING STAGGERED RELATIVE TO THE OPENINGS IN THE ADJACENT ROWS ON EITHER SIDE THEREOF, EACH OF SAID OPENINGS RECEIVING A HARDENED STEEL BALL WHICH PROJECTS FROM THE JAW BODY TO PROVIDE A WORKING SURFACE TO MATERIAL IN ALL DIRECTIONS OF MOVEMENT OF SUCH MATERIAL OVER SAID JAW BODY AND MEANS FOR REMOVABLY SECURING SAID BALL TO SAID BODY. 